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1940's making of ruby rods


#1

I understand before and during World War II Russia was making ruby
rods. Does any one have any as to how the rods were
made, such as refractive index, critical angle, or what the material
is made of. A friend of mine tested some on a low grade diamond
tester and the test as diamond or having some sort of carbon in them.
Also what is GGG or Gadolinium Gallion Garnet?

Thanks!
Anne


#2

The material was made of corundum. 100% real ruby, without all that
pesky nature stuff involved. It was done since the very early 20th
century.

I think you’re thinking of Jan Czochralski, a Pole. He invented a
process for making long cylindrical crystals, named the Czochralski
Process. Here’s a neat Wikipedia article about it.

Willis


#3

Gadolinium Gallium Garnet, a synthetic non-silicate garnet like
Yttrium Aluminum Garnet (YAG) is grown by the Czochralski technique
(crystal pulling) and was evaluated as a possible laser host.
Properties very much like YAG. Sapphire rods (single crystal Al2O3)
were grown by Union Carbide Corporation Linde Division in East
Chicago Indiana by the Verneuil technique (flame fusion) for
applications where the abrasion resistance of sapphire made them
worth the effort and cost to produce (yarn guides for knitting
machines were one application). 0.05% chromium in pure colorless
sapphire makes it red (ruby). Sapphire was first grown in France by
Verneuil and have since been produced by that technique world wide.
Today ruby crystals are grown by the Czochralski technique for
applications requiring high optical and crystallographic quality and
by the Verneuil technique for less demanding applications. Some
sapphire and ruby is also grown from solution (hydrothermal and flux
techniques) but not in economically significant amounts.


#4

Dear Anne, I can help you a little on your second question. GGG
(Gadolinium Gallium Garnet) is a synthetic mineral whose chemical
composition puts it in the Garnet continuum.It is from transparent
through light brown, yellow, orange, blue, with the addition of
various dopants. Hardness: 6.5-7.5, R.I. 1.970. Formed through the
Czochralski Method. It was used as a diamond simulant, and also had
some industrial applications (optical components, etc.)

Hope this helps a little.
Gary Strickland, GJG


#5

Further to the other answers the flame fusion process is also known
as a Chalameau furnace from the French for a type of pipe. It was
invented back in the 19th century. this produces boules which are
highly strained crystals and generally fracture in half. Pulled
crystals are grown from a single crystal seed and a powder in a
laser or RF furnace where the crystal is heated to its melting point
and then pulled through the furnace and the powder melts and
crystallises in the same orientation behind it. Also works with
metals- Nickel superalloy turbine blades for jet engines are made
this way. Gadolinium Gallium Garnet is a synthetic garnet that is
used in lasers and some semiconductor substrates instead of YAG or
Magalox, which are all of the same crystal system. All were also used
as diamond simulants until CZ was developed.

Nick Royall